Tomtom go700

[Geoff Ranby]

I replaced the battery on my sat nav and whilst I’m charging it there is a flashing X could you advice me what this means and what I can do to fix it.

 

[canderson]

Are you saying that the flashing red X ONLY occurs during charging? I don't think I've ever seen that.
Normally, that's an indication of a much bigger problem (device can't find any system code to run), and continues to occur until the problem is resolved.
This could well happen if the hard drive wasn't properly connected. Any chance that might be the case?